How to tweak newsletter so Spam Sieve doesn't classify it as spam

I’m preparing an newsletter to send out to subscribers, but it’s marked as spam by Spam Sieve on my wife’s Mac. Can anyone interpret the the reasons so I can tweak the newsletter to prevent this?

Predicted: Spam (73)
Subject: WolfQuest News - February 2017
From: news@wolfquest.org
Identifier: kKI/GxWpxw9kyqxXd/BUEQ==
Reason: P(spam)=1.000[0.500], bias=0.000, revived(1.000), revived(1.000), specimen(1.000), specimen(1.000), A:READ(1.000), ^a-width-660(1.000), U:wq(0.000), U:wq(0.000), ravens!(0.999), ravens!(0.999), R:^75-168-146-229^mpls^qwest^net(0.001), fall!(0.001), fall!(0.001), U:660(0.999), C:min(0.001)
Date: 2017-02-16 15:08:53 -0600 (CST)

thanks!
Dave

The reasons here depend on the particular messages that your wife had trained SpamSieve with. Other spam filters, even someone else’s copy of SpamSieve, could have very different results. For example, “revived”, “specimen”, and “ravens!” had apparently only appeared in her previous spam messages. For other people, these words might not have such a spammy history, if they had even been seen at all.

Thanks for the reply. So I guess it’s just bad luck.

Dave